Effect of organic and inorganic sources of nutrients on rice (Oryza sativa) - wheat (Triticum aestivum) cropping system

Abstract

A field experiment was conducted during 2002-03 to 2004-05 at Malan, Himachal Pradesh, to explore the possibility of an alternative to farmyard manure (FYM) as a component of integrated nutrient management in rice (Oryza sativa L.) - wheat (Trticum aestivum L. emend. Fiori & Paol.) system. Five organic sources, viz. FYM 5 Uha gobhi sarson straw 5 Uha, mushroom spent compost 2.5 Uha, FYM 2.5 tlha t gobhi sarson straw 2.5 Uha, FYM 2.5 Uha t mushroom spent compost 1.25 Uha, were applied in all possible combinations at three fertility levels, viz. 50, 100 and 150% of recommended fertilizer dose (RDF) to rice crop. Direct and residual effects of organic sources significantly affected the productivity of rice-wheat cropping system. Statistically equal rice and wheat yields were obtained with application of FYM 5 tlha (5.03 Uha rice, 2.48 Uha wheat) and FYM 2.5 Uha t mushroom spent com- post 1.25 Uha (4.94 Uha, 2.33 Uha), whereas gobhi sarson straw 5 Uha recorded lower yields (4.24 Uha, 1.99 tiha). Rice responded significantly up to 100% recommended dose (4.77 Uha); residual effects of fertility levels on wheat did not differ significantly. Standard control (1 00% RDF to both crops) resulted in significantly higher grain yield of wheat compared with mean of others receiving only 50% RDF. Nutrient uptake uptake (1 59.1 kg N, 35.0 kg P and 147.9 kg Wha) and net returns (Rs 41,5351ha) from the rice-wheat cropping system recorded higher values with FYM 5 Uha, followed by FYM 2.5 Uha t mushroom spent compost 1.25 Uha (1 55.0 kg N, 32.5 kg P and 139.0 kg W ha; Rs 39,132lha). The soil-available NPK status remained fairly constant under different treatments. Thus, FYM 2.5 tlha t mushroom spent compost 1.25 tlha applied to rice helped in sustained productivity and profitability of the cropping system statistically equal to that with FYM 5 tlha.